Sprinkler base



FIG. 1 is a perspective view of a sprinkler base showing my new design;

FIG. 2 is a top plan view thereof;

FIG. 3 is a front elevational view showing my new design; and,

FIG. 4 is a left side elevational view thereof.

The bottom view is unornamented and forms no part of the claimed design. The left side view is a mirror image of the right side view. 

The ornamental design for a sprinkler base, as shown and described. 